By Xinhua
Beijing : U.S. researchers say they have made the blackest substance on Earth. So black it absorbs more than 99.9 percent of light.
The material is made from tiny tubes of carbon standing on end and is almost 30 times darker than a carbon substance used by the National Institute of Standards and Technology as the current benchmark of blackness.
“All the light that goes in is basically absorbed,” Pulickel Ajayan, who led the research team at Rice University in Houston, said Tuesday in a telephone interview. “It is almost pushing the limit of how much light can be absorbed into one material.”
The substance has a total reflective index of 0.045 percent — which is more than three times darker than the nickel-phosphorus alloy that now holds the record as the world’s darkest material.
Basic black paint, by comparison, has a reflective index of 5 percent to 10 percent.
Ajayan said the material could be used in solar energy conversion. “You could think of a material that basically collects all the light that falls into it,” he said.
It could also could be used in infrared detection or astronomical observation.